Telepresence Between a Multi-Unit Location and a Plurality of Single Unit Locations

ABSTRACT

Performing a videoconference. The videoconference may be established at a first videoconferencing location between at least three videoconferencing locations. The locations may include the first location, a second location, and a third location. The first location may maintain a plurality of videoconferencing units and the second and third locations may each maintain a single videoconferencing unit. A first videoconferencing unit of the first location acts as a multipoint control unit (MCU) of the videoconference. The MCU may receive respective videoconferencing information from each videoconferencing unit of the videoconference. The MCU may provide active videoconferencing information of an active participant to ones of the videoconferencing units at the second and third locations corresponding to non-active participants. The MCU may provide second and third videoconference information from the videoconferencing units of the second and third locations for presentation at the first location. This provision may be performed independently of the active participant.

FIELD OF THE INVENTION

The present invention relates generally to videoconferencing and, morespecifically, to a method for conducting a telepresence videoconferencewith single unit locations.

Description of the Related Art

Videoconferencing may be used to allow two or more participants atremote locations to communicate using both video and audio. Eachparticipant location may include a videoconferencing system forvideo/audio communication with other participants. Eachvideoconferencing system may include a camera and microphone to collectvideo and audio from a first or local participant to send to another(remote) participant, as well as a display and speaker(s) to reproducevideo and audio received from one or more remote participants. Eachvideoconferencing system may also be coupled to (or comprise) a computersystem to allow additional functionality into the videoconference. Forexample, additional functionality may include data conferencing(including displaying and/or modifying a document for both participantsduring the conference).

An emerging trend in videoconferencing is to utilize multiple displaysand/or multiple cameras at one or more locations of a videoconference. Amulti-screen telepresence setup typically requires the use of a hardwaremultipoint conferencing unit (MCU) in order to perform the audio/videoswitching and mixing necessary for such videoconferences to happen.However, these dedicated MCU systems are expensive and hence increasethe cost of the multi-screen telepresence deployments significantly. Inaddition, improved methods are desired for presenting activeparticipants in a videoconference where at least one of the locationsemploys multi-screen telepresence. Accordingly, improvements invideoconferencing are desired.

SUMMARY OF THE INVENTION

Various embodiments are presented of a system and method for performinga videoconference between a first location with a plurality ofconferencing units and a plurality of other locations with singleconferencing units.

The videoconference may be initially established, at a firstvideoconferencing location, between at least three videoconferencinglocations (e.g., between the first videoconferencing location and atleast two other videoconferencing locations). The firstvideoconferencing location may include a plurality of displays, aplurality of corresponding video inputs, one or more audio inputs, and aplurality of corresponding videoconferencing units (e.g., codecs).Second and third videoconferencing locations may only include singleendpoints, e.g., including one or more respective displays, one or morerespective video inputs, a respective corresponding videoconferencingunit (e.g., a single codec), and one or more respective audio inputs. Inone embodiment, a first endpoint at the first videoconferencing may actas host or MCU of the videoconference.

Respective videoconferencing information may be received from eachvideoconferencing unit of the videoconference. For example, the host mayreceive audio and video information from each videoconferencing unit inthe videoconference.

An active participant may be determined for the videoconference, e.g.,based on the received videoconferencing information. The activeparticipant may be determined in any of a variety of ways. For example,the participant with the loudest current audio level (or the largestamount of accumulated audio signal energy) may be determined to be theactivate participant.

Based on this determination, active videoconferencing information of anactive participant may be provided to ones of the videoconferencingunits at the second and third videoconferencing locations correspondingto non-active participants. The videoconferencing information mayinclude the audio and video corresponding to the active participant.

Additionally, second and third videoconferencing information from thevideoconferencing units of the second and third videoconferencinglocations may be provided for presentation at the firstvideoconferencing location. For example, the second videoconferencinginformation may be provided for presentation by the firstvideoconferencing unit of the first videoconferencing location and thethird videoconferencing information may be provided for presentation bythe second videoconferencing unit of the first videoconferencinglocation.

The provision of the second and third videoconferencing information tothe videoconferencing units of the first videoconferencing location maybe performed regardless of the determined active participant. In otherwords, in one embodiment, since all of the participants at the firstlocation can hear and see each other, and see all of the displays in thefirst location, the displays at the first location may be dedicated tothe second and third locations and may not change throughout thevideoconference, regardless of the determined active participant.However, since the participants at the second and third location do nothave this ability, the participant at each of these locations maycontinually switch to viewing/hearing the active participant. However,each location may not view and/or hear the active participant when he isthe active participant, and may instead view/hear a previously activeparticipant.

For example, if the active participant is determined to be avideoconferencing unit of the first videoconferencing location, theactive videoconferencing information may correspond to thatvideoconferencing unit. Accordingly, the active videoconferencinginformation may be provided to both of the videoconferencing units ofthe second and third videoconferencing locations. In this case, in oneembodiment, none of the videoconferencing units of the firstvideoconferencing location may present the active videoconferencinginformation of the videoconferencing unit of the first videoconferencing location.

Alternatively, if the active participant is determined to be thevideoconferencing unit of the second videoconferencing location, theactive videoconferencing information (and accordingly, the activeparticipant) may correspond to that videoconferencing unit. Accordingly,the active videoconferencing information may not be provided to thevideoconferencing unit of the second videoconferencing location.Instead, the other videoconferencing information (e.g., of a previousactive participant) may be provided to the second videoconferencinglocation. However, the active videoconferencing information may still beprovided to the videoconferencing unit of the third videoconferencinglocation.

Note that the first videoconferencing unit may provide composite video(continuous presence with video images of multiple participants) to oneor more of the videoconferencing units (e.g., rather than a singlewindow video view). For example, the first videoconferencing unit maygenerate one or more composite videos for various ones of thevideoconferencing units. In one embodiment, the composite video maycomprise video from a plurality of the first videoconferencing unit ofthe first location, the second videoconferencing unit of the firstlocation, the videoconferencing unit from the second location, or thevideoconferencing unit from the third location. For example, for thesecond videoconferencing unit, a composite video may be generated whichincludes the first and second units of the first location and the unitfrom the third location, although other embodiments are envisioned. Insome embodiments, the composite video may include other video inputs,e.g., from presentations or other sources (such as computers, DVDs,digital video players, etc.).

Additionally, note that the method described above may be extended to athree unit system at the first participant location and a fourth singleunit participant location. Accordingly, the first videoconferencing unitmay provide active videoconferencing information to thevideoconferencing unit of the fourth videoconferencing location when theactive videoconferencing information does not correspond to the fourthvideoconferencing location. Additionally, the first videoconferencingunit may provide fourth videoconference information from thevideoconferencing unit of the fourth videoconferencing location forpresentation at the first videoconferencing location, e.g., by the thirdvideoconferencing unit of the first videoconferencing location.Similarly, the embodiments described above may be extended to n units atthe first location and n single units. In further embodiments, throughcompositing, more than n single units may be accommodated. Additionally,it may be possible to connect more than one multi-unit location togetheras well as further single unit locations, as desired.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention may be obtained when thefollowing detailed description is considered in conjunction with thefollowing drawings, in which:

FIGS. 1 and 2 illustrate exemplary videoconferencing system participantlocations, according to an embodiment;

FIG. 3 illustrates a multi-way multi-screen telepresence setup accordingto one embodiment;

FIG. 4 illustrates coupled single unit and multi-unit conferencinglocations for a videoconference, according to one embodiment;

FIGS. 5 and 6 illustrate various embodiments of a three endpointtelepresence room setup; and

FIG. 7 is a flowchart diagram illustrating exemplary methods forperforming a videoconference with a multi-unit conferencing location anda plurality of single unit conferencing locations, according to someembodiments.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof are shown by way ofexample in the drawings and will herein be described in detail. Itshould be understood, however, that the drawings and detaileddescription thereto are not intended to limit the invention to theparticular form disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the present invention as defined by the appendedclaims. Note that the headings are for organizational purposes only andare not meant to be used to limit or interpret the description orclaims. Furthermore, note that the word “may” is used throughout thisapplication in a permissive sense (i.e., having the potential to, beingable to), not a mandatory sense (i.e., must). The term “include”, andderivations thereof, mean “including, but not limited to”. The term“coupled” means “directly or indirectly connected”.

DETAILED DESCRIPTION OF THE EMBODIMENTS Incorporation by Reference

U.S. patent application titled “Video Conferencing System Transcoder”,Ser. No. 11/252,238, which was filed Oct. 17, 2005, whose inventors areMichael L. Kenoyer and Michael V. Jenkins, is hereby incorporated byreference in its entirety as though fully and completely set forthherein.

U.S. patent application titled “Multiway Telepresence without a HardwareMCU”, Ser. No. 12/779,424, whose inventors are Hrishikesh G. Kulkarni,Prithvi Ranganath, Raghuram Belur, and Sandeep Lakshmipathy, is herebyincorporated by reference in its entirety as though fully and completelyset forth herein.

FIGS. 1 and 2—Exemplary Participant Locations

FIG. 1 illustrates an exemplary embodiment of a videoconferencingparticipant location including a single endpoint. The videoconferencingsystem 103 may have a system codec 109 to manage both a speakerphone105/107 and videoconferencing hardware, e.g., camera 104, display 101,speakers 171, 173, 175, etc. The speakerphones 105/107 and othervideoconferencing system components may be coupled to the codec 109 andmay receive audio and/or video signals from the system codec 109.

In some embodiments, the participant location may include camera 104(e.g., an HD camera) for acquiring images (e.g., of participant 114) ofthe participant location. Other cameras are also contemplated. Theparticipant location may also include display 101 (e.g., an HDTVdisplay). Images acquired by the camera 104 may be displayed locally onthe display 101 and/or may be encoded and transmitted to otherparticipant locations in the videoconference.

The participant location may further include one or more input devices,such as the computer keyboard 140. In some embodiments, the one or moreinput devices may be used for the videoconferencing system 103 and/ormay be used for one or more other computer systems at the participantlocation, as desired.

The participant location may also include a sound system 161. The soundsystem 161 may include multiple speakers including left speakers 171,center speaker 173, and right speakers 175. Other numbers of speakersand other speaker configurations may also be used. The videoconferencingsystem 103 may also use one or more speakerphones 105/107 which may bedaisy chained together.

In some embodiments, the videoconferencing system components (e.g., thecamera 104, display 101, sound system 161, and speakerphones 105/107)may be coupled to a system codec 109. The system codec 109 may be placedon a desk or on a floor. Other placements are also contemplated. Thesystem codec 109 may receive audio and/or video data from a network,such as a LAN (local area network) or the Internet. The system codec 109may send the audio to the speakerphone 105/107 and/or sound system 161and the video to the display 101. The received video may be HD videothat is displayed on the HD display. The system codec 109 may alsoreceive video data from the camera 104 and audio data from thespeakerphones 105/107 and transmit the video and/or audio data over thenetwork to another conferencing system. The conferencing system may becontrolled by a participant or user through the user input components(e.g., buttons) on the speakerphones 105/107 and/or input devices suchas the keyboard 140 and/or the remote control 150. Other systeminterfaces may also be used.

In various embodiments, a codec may implement a real time transmissionprotocol. In some embodiments, a codec (which may be short for“compressor/decompressor”) may comprise any system and/or method forencoding and/or decoding (e.g., compressing and decompressing) data(e.g., audio and/or video data). For example, communication applicationsmay use codecs for encoding video and audio for transmission acrossnetworks, including compression and packetization. Codecs may also beused to convert an analog signal to a digital signal for transmittingover various digital networks (e.g., network, PSTN, the Internet, etc.)and to convert a received digital signal to an analog signal. In variousembodiments, codecs may be implemented in software, hardware, or acombination of both. Some codecs for computer video and/or audio mayinclude MPEG, Indeo™, and Cinepak™, among others.

In some embodiments, the videoconferencing system 103 may be designed tooperate with normal display or high definition (HD) displaycapabilities. The videoconferencing system 103 may operate with networkinfrastructures that support T1 capabilities or less, e.g., 1.5mega-bits per second or less in one embodiment, and 2 mega-bits persecond in other embodiments.

Note that the videoconferencing system(s) described herein may bededicated videoconferencing systems (i.e., whose purpose is to providevideoconferencing) or general purpose computers (e.g., IBM-compatiblePC, Mac, etc.) executing videoconferencing software (e.g., a generalpurpose computer for using user applications, one of which performsvideoconferencing). A dedicated videoconferencing system may be designedspecifically for videoconferencing, and is not used as a general purposecomputing platform; for example, the dedicated videoconferencing systemmay execute an operating system which may be typically streamlined (or“locked down”) to run one or more applications to providevideoconferencing, e.g., for a conference room of a company. In otherembodiments, the videoconferencing system may be a general use computer(e.g., a typical computer system which may be used by the general publicor a high end computer system used by corporations) which can execute aplurality of third party applications, one of which providesvideoconferencing capabilities. Videoconferencing systems may be complex(such as the videoconferencing system shown in FIG. 1) or simple (e.g.,a user computer system 200 with a video camera, input devices,microphone and/or speakers such as the videoconferencing system of FIG.2). Thus, references to videoconferencing systems, endpoints, etc.herein may refer to general computer systems which executevideoconferencing applications or dedicated videoconferencing systems.Note further that references to the videoconferencing systems performingactions may refer to the videoconferencing application(s) executed bythe videoconferencing systems performing the actions (i.e., beingexecuted to perform the actions).

The videoconferencing system 103 may execute various videoconferencingapplication software that presents a graphical user interface (GUI) onthe display 101. The GUI may be used to present an address book, contactlist, list of previous callees (call list) and/or other informationindicating other videoconferencing systems that the user may desire tocall to conduct a videoconference.

The videoconferencing systems 103 and 200 are shown as including asingle endpoint (e.g., a single codec, display, camera, etc.). In amulti-screen telepresence setup, a videoconferencing location mightinclude multiple such endpoints. For example, a common telepresencesetup includes three displays, with corresponding cameras, codecs,and/or other equipment, as desired. The three displays may be placedside-by-side to provide a more realistic feeling of being in the sameroom for the videoconference participants at each location. Othernumbers of endpoints per location and other display setups are alsocontemplated. For example, one participant or videoconference locationmay include a telepresence setup which may connect to other participantsor videoconference locations which include only a singlevideoconferencing endpoint.

FIG. 3—Multi-Unit Coupled Conferencing systems

FIG. 3 illustrates a multi-screen multi-way telepresence configurationof videoconferencing systems according to one embodiment. As shown, eachconferencing location may include multiple endpoints. Thus, the firstlocation may include participant endpoints L1, C1, and R1, while thesecond and third locations may include participant endpoints L2, C2, R2,and L3, C3, R3 respectively. Each endpoint may include a conferencingunit, such as shown in and described with respect to FIGS. 1 and 2according to various embodiments. In the exemplary embodiment shown,there are three locations (e.g., rooms), each including three endpoints.

Each endpoint at each location may be coupled to one or more respectiveendpoints at the other videoconferencing locations. In some embodiments,the endpoints (e.g., the endpoints' codecs) at one location may act ashosts for the respective endpoints at the other locations to which theyare coupled. For example, in the exemplary configuration shown in FIG.3, the endpoints at the first location may act as the host endpoints.Thus, the L2 and L3 endpoints at the second and third locations may bothcouple to the L1 endpoint, while the C2 and C3 endpoints couple to theC1 endpoint, and the R2 and R3 endpoints couple to the R1 endpoint. Inother words, in some embodiments, the telepresence setup shown in FIG. 3may be accomplished as three separate (but potentially coupled, e.g., asdescribed below) videoconferences.

The endpoints at each location may also be coupled to each other in anyof a variety of ways. For example, the codecs of the endpoints at eachlocation may communicate with each other, e.g., in order to determineinitial routing of connections between locations. As another example,embodiments are contemplated in which the codecs of the endpoints ateach location may each be coupled to an audio mixer, where the audiomixer is configured to mix together audio signals from the endpoints atthat location, such that each codec may receive a mixed audio signalincluding all of the audio signals from that codec's location.

Since there may be at least three videoconferencing locationsparticipating in the videoconference, there may be more video inputsignals than any single location may be capable of displaying. It may bepossible to use dedicated multipoint control hardware to create acomposite image (also referred to as a continuous presence image) frommultiple video inputs, however, this may in some embodiments be anundesirable solution. More specifically, dedicated multipoint controlhardware (i.e., that is separate from the videoconferencing units) maytypically be relatively expensive, potentially reducing the feasibilityof implementing telepresence systems for some organizations. Instead,one or more of the videoconferencing units may act as the MCU, asdescribed below.

Accordingly, in some embodiments, a switching scheme may be implemented,e.g., in order that each endpoint may display an appropriate video inputsignal at any given time. According to some embodiments, themulti-screen multi-way telepresence videoconference illustrated in FIG.3 may be capable of operating in either a “segment switching mode” or a“site switching mode”, as described in the U.S. patent applicationtitled “Multiway Telepresence without a Hardware MCU”, which wasincorporated by reference above. FIG. 3 illustrates an embodiment ofsite switching where the current dominant talker is in location 1.Accordingly, locations 2 and 3 are both displaying location 1 on allthree screens. Location 1 is displaying the previous dominant talkers oflocation 2.

FIG. 4—Single Unit and Multi-Unit Coupled Conferencing Locations

FIG. 4 illustrates a multi-unit telepresence videoconferencing locationcoupled to a plurality of single unit videoconferencing locationsaccording to one embodiment. The conferencing systems may be operable toperform the methods described herein. As shown, a first location mayinclude participant endpoints L1, C1, and R1, while the second, third,and fourth locations may include single respective participantconferencing endpoints 2, 3, and 4 respectively. Each endpoint at thelocations 2, 3, and 4 may be similar to that shown in and described withrespect to FIGS. 1 and 2, according to various embodiments. However, theendpoints at location 1 may be similar to that described with respect toFIGS. 3, 5, and 6, among other possible variations. Additionally, eachunit may have been associated or coupled to more than one display, videoinput, video output, audio input, and audio output, as desired.Regardless, locations 2, 3, and 4, may be designed for a singleparticipant with a single videoconferencing unit.

As shown, each endpoint at locations 2, 3, and 4 may be coupled to ahost endpoint at the first location, e.g., C1. C1 may act as an MCU forL1, C1, R1, 2, 3, and 4. For example, C1 may forward videoconferencinginformation between L1 and R1 and locations 2, 3, and 4. Morespecifically, C1 may receive information from 2 and forward thatinformation for presentation on L1 and may receive information from 3and forward that information for presentation on R1. For locations 2, 3,and 4, C1 may provide various different audio and video depending onvideoconferencing conditions, as described in more detail below.

Alternatively, each endpoint at locations 2, 3, and 4 may be coupled torespective endpoints at location 1. In some embodiments, the endpoints(e.g., the endpoints' codecs) at the first location may act as hosts forthe respective endpoints at the other locations to which they arecoupled. Thus, L1 may be the host endpoint for L1 and location 2; C1 maybe the host endpoint for C1 and location 3; and R1 may be the hostendpoint for R1 and location 3. In other words, in some embodiments, thetelepresence setup shown in FIG. 4 may be accomplished as three separate(but potentially coupled) videoconferences.

Similar to above, the endpoints at the first location may also becoupled to each other in any of a variety of ways. For example, thecodecs of the first location may communicate with each other, e.g., inorder to determine initial routing of connections between locations. Asanother example, embodiments are contemplated in which the codecs of thefirst endpoint may each be coupled to an audio mixer, where the audiomixer is configured to mix together audio signals from the endpoints atthat location, such that each codec may receive a mixed audio signalincluding all of the audio signals from that codec's location.

Since there may be at least three videoconferencing locationsparticipating in the videoconference, there may be more video inputsignals than any single location may be capable of displaying (e.g., atlocations 2, 3, and 4). It may be possible to create a composite imagefrom multiple video inputs (e.g., for the first location or for all ofthe other locations for a given location). For example, the centervideoconferencing unit may generate composite images for locations 2, 3,and 4. As described herein, the center videoconferencing unit may act asthe MCU for all of the remaining videoconferencing units in thevideoconference. Further details are provided with respect to FIG. 7below.

FIGS. 5 and 6—Multi-Unit Room Configuration

FIGS. 5 and 6 illustrate aspects of an exemplary multi-unit (e.g.,telepresence) location configuration according to various embodiments.According to some embodiments, the first videoconferencing location ofFIG. 4 may be implemented using one or both of the exemplarytelepresence room configurations shown in FIGS. 5 and 6, e.g., toimplement a method for performing a videoconference according to any ofthe various embodiments described below with respect to FIG. 7.

In the embodiment of FIG. 5, the telepresence room 500 may include threeendpoints: a “left” endpoint, a “center” endpoint, and a “right”endpoint. Each endpoint may include a codec 504, and an audio input 506,such as a microphone or microphone array. Each endpoint may also includea video input (not shown) such as a video camera, a display (not shown)for displaying videoconferencing information from other locations, andany of various other videoconferencing equipment, as desired.

As shown in FIG. 5, each audio input may be configured as aunidirectional audio input e.g., with a directionally oriented “audiopickup cone” 508. It should be noted that although the audio pickupcones 508 are shown as being essentially cone shaped, the actual shapeof the audio pickup cone may be any of a variety of shapes; for example,in some embodiments the actual audio pickup field may a cardioid.

By using a unidirectional audio input configuration for each endpoint ata location, it may be possible to isolate corresponding portions of atelepresence room. In other words, if the audio pickup cones 508 of theaudio inputs are substantially non-overlapping, a videoconferenceparticipant speaking in the audio pickup cones 408 a of correspondingMicPod 506 a may not produce a noticeable audio input signal in theother MicPods 506 b, 506 c. This separation of audio inputs may beimportant in order to allow for the possibility of a segment-switchingvideoconference configuration, as will be described below.

In some embodiments, the respective audio inputs 506 a, 506 b, 506 c mayprovide received audio input signals to their respective codecs 504 a,504 b, 504 c directly as shown in FIG. 5. Alternatively, in someembodiments it may be preferable that the respective audio inputs 506 a,506 b, 506 c provide received audio input signals to a mixer. Anexemplary such embodiment is shown in FIG. 6.

In FIG. 6, participants 610 a-c are located within the respective audiopickup cones of audio inputs (e.g., microphone) 606 a-c in telepresenceroom 600. Thus, if participant 610 a speaks, audio input 606 a shouldreceive an audio input signal, while audio inputs 606 b, 606 c shouldnot. However, the audio input signals from each of the audio inputs 606a-c may be provided to a mixer 602, which may be configured to mix thereceived audio input signals to produce a mixed audio signal. The mixedaudio signal may retain information indicating from which audio inputwhich audio input signal is received; for example, the mixed audiosignal may include respective channels for each of audio inputs 606 a-c.

The mixer 602 may further be configured to provide the mixed audiosignal to one or more of the codecs in the telepresence room. Forexample, as shown, the mixer 602 may be configured to provide the mixedaudio signal to each of the left codec 604 a (e.g., corresponding to theaudio input 606 a), the center codec 604 b (e.g., corresponding to theaudio input 606 b), and the right codec 604 c (e.g., corresponding tothe audio input 606 c).

Alternatively, in some embodiments the mixer 602 may be configured toprovide the mixed audio signal to a subset of the codecs in thetelepresence room 600. For example, in some embodiments the mixer 602may only provide the mixed audio signal to the center codec 604 b, whichmay then provide the mixed audio signal (or a portion thereof) to theleft codec 604 a and the right codec 604 c.

Each codec may be configured to determine, from the mixed audio signal,whether or not its corresponding audio input is receiving an audiosignal (e.g., from a participant speaking) This may allow the codec todetermine whether a switching condition has occurred. Alternatively, onecodec at a location may operate as a “master” codec, e.g., may act as anMCU for all of the videoconferencing units (including the localvideoconferencing units). The master codec may determine a switchingcondition from received audio and provide corresponding video signalsfor display, described in more detail below.

FIG. 7—Conducting a Multi-Screen Videoconference

FIG. 7 illustrates embodiments of a method for conducting avideoconference with a multi-screen location with a plurality of singlescreen locations. The methods shown in FIG. 7 may be used in conjunctionwith any of the computer systems or devices shown in the above Figures,among other devices. For example, the methods of FIG. 7 may apply to anembodiment where a videoconference is conducted between a plurality ofvideoconferencing locations, such as shown in FIG. 4. The system, or aportion thereof (e.g., a single location), may be configured to performthe method, as described below. In various embodiments, some of themethod elements shown may be performed concurrently, performed in adifferent order than shown, or omitted. Additional method elements mayalso be performed as desired. As shown, the method may operate asfollows.

In 702, the videoconference may be established, at a firstvideoconferencing location, between at least three videoconferencinglocations (e.g., at least two other videoconferencing locations). Thefirst videoconferencing location may include a plurality of displays, aplurality of corresponding video inputs, and a plurality ofcorresponding videoconferencing units (e.g., codecs). In someembodiments, the first videoconferencing location may also include aplurality of corresponding audio inputs. The audio inputs may be coupledto mixer (e.g., an audio mixer), which may be coupled to each of theplurality of videoconferencing units. Second and third videoconferencinglocations may only include single endpoints, e.g., including one or morerespective displays, one or more respective video inputs, a respectivecorresponding videoconferencing unit, and one or more respective audioinputs.

In one embodiment, the videoconference may be established according tothe following descriptions. The first videoconferencing location mayinclude a plurality of videoconferencing units. For example, there maybe three videoconferencing units in the first location L1, C1, and R1.At a plurality of other locations, there are only singlevideoconferencing units.

In one particular embodiment, all the other locations initially attemptto connect (or call) C1 at the first location, although otherembodiments are envisioned. For example, a videoconferencing unit (2) ata second location may call C1 (e.g., which may be a controlling endpointof the first location, e.g., the MCU of the videoconference). Inresponse, C1 may determine that this is a single videoconferencingendpoint location (e.g., through proprietary messaging, 2 may be able totell C1 that it is a single screen room codec) and accepts the call toitself. Later, a videoconferencing unit (3) at a third location may callC1. In response, C1, determining that 3 is single videoconferencing unitlocation, and that it already has one call, checks with L1 if it cantake a call and if it can, it may forward communications from 3 to L1for display. Additionally, a videoconferencing unit (4) at a fourthlocation may call C1. C1, seeing 4 is single screen, and that itself andL1 already are displaying information from 3 and 2 respectively,forwards communication from 4 to R1 for display. This may continue untilC1 realizes it can take no more incoming calls from singlevideoconferencing endpoint locations (e.g., that there are no moreremaining screens or videoconferencing units at the first location orthat the C1 unit has run out of ports to handle incoming conferences).However, it should be noted that other embodiments are envisioned, e.g.,where the L1, C1, and R1 each make a connection with 3, 2, and 4,respectively, e.g., without the information being forwarded through C1.Such connections could be initially handled and transferred from C1 orcould be achieved by each remote conferencing unit “calling” orinitiating a connection themselves (e.g., or vice versa, from L1 andR1's point of view). In such embodiments, there may not be a masterendpoint at the first location.

Thus, in one embodiment, in 702, a first endpoint at the firstvideoconferencing may act as host or MCU of the videoconference.

In 704, respective videoconferencing information may be received fromeach videoconferencing unit of the videoconference. For example, C1(e.g., acting as the MCU) may receive audio and video information fromeach videoconferencing unit (e.g., videoconferencing units L1, R1, 2, 3,4, and its own audio and video information). Note that where mixed audiois received for the entirety of the first location, C1 may receive onlythe mixed audio for the first location instead of individual audio fromitself, L1, and R1.

In 706, an active participant may be determined for the videoconference,e.g., based on the information received in 704. The active participantmay be determined in any of a variety of ways. For example, theparticipant with the loudest current audio level may be determined to bethe activate participant. Alternatively, the participant with thelargest audio energy level (e.g., averaged over a specified amount oftime) may be determined to be the active participant. In furtherembodiments, the participant whose current audio level exceeds abaseline level (for that location or participant) by the largest amountmay be determined to be the active participant. Thus, the activeparticipant may be the participant who is speaking (or speaking moreloudly) in the videoconference.

In 708, based on the determination of 706, active videoconferencinginformation of an active participant may be provided to ones of thevideoconferencing units at the second and third videoconferencinglocations corresponding to non-active participants. Thevideoconferencing information may include the audio and videocorresponding to the active participant.

In 710, second and third videoconferencing information from thevideoconferencing units of the second and third videoconferencinglocations may be provided for presentation at the firstvideoconferencing location. For example, the second videoconferencinginformation may be provided for presentation by the firstvideoconferencing unit of the first videoconferencing location and thethird videoconferencing information may be provided for presentation bythe second videoconferencing unit of the first videoconferencinglocation.

The provision of the second and third videoconferencing information tothe videoconferencing units of the first videoconferencing location maybe performed regardless of the active participant determined in 706. Inother words, in one embodiment, since all of the participants at thefirst location can hear and see each other, and all of the displays inthe first location, the displays at the first location may be dedicatedto the second and third locations and may not change throughout thevideoconference. However, since the participants at the second and thirdlocation do not have this ability, the participant at each of theselocations may continually switch to viewing/hearing the activeparticipant. However, each location may not view and/or hear the activeparticipant when he is the active participant, and may instead view/heara previously active participant.

For example, if the active participant is determined to be avideoconferencing unit of the first videoconferencing location in 706,the active videoconferencing information may correspond to thatvideoconferencing unit. Accordingly, the active videoconferencinginformation may be provided to both of the videoconferencing units ofthe second and third videoconferencing locations. In this case, in oneembodiment, none of the videoconferencing units of the firstvideoconferencing location may present the active videoconferencinginformation of the videoconferencing unit of the first videoconferencinglocation.

Alternatively, if the active participant is determined to be thevideoconferencing unit of the second videoconferencing location in 706,the active videoconferencing information (and accordingly, the activeparticipant) may correspond to that videoconferencing unit. Accordingly,the active videoconferencing information may not be provided to thevideoconferencing unit of the second videoconferencing location.Instead, the other videoconferencing information (e.g., of a previousactive participant) may be provided to the second videoconferencinglocation. However, the active videoconferencing information may still beprovided to the videoconferencing unit of the third videoconferencinglocation.

Note that the first videoconferencing unit may provide composite videoto one or more of the videoconferencing units (e.g., rather than asingle video screen, as shown in FIG. 4). For example, the firstvideoconferencing unit may generate one or more composite videos forvarious ones of the videoconferencing units. In one embodiment, thecomposite video may comprise video from a plurality of the firstvideoconferencing unit of the first location, the secondvideoconferencing unit of the first location, the videoconferencing unitfrom the second location, or the videoconferencing unit from the thirdlocation. For example, for the second videoconferencing unit, acomposite video may be generated which includes the first and secondunits of the first location and the unit from the third location,although other embodiments are envisioned. In some embodiments, thecomposite video may include other video inputs, e.g., from presentationsor other sources (such as computers, DVDs, digital video players, etc.).

Additionally, note that the method described above may be extended to athree unit system at the first participant location and a fourth singleunit participant location. Accordingly, the first videoconferencing unitmay provide active videoconferencing information to thevideoconferencing unit of the fourth videoconferencing location when theactive videoconferencing information does not correspond to the fourthvideoconferencing location. Additionally, the first videoconferencingunit may provide fourth videoconference information from thevideoconferencing unit of the fourth videoconferencing location forpresentation at the first videoconferencing location, e.g., by the thirdvideoconferencing unit of the first videoconferencing location.Similarly, the embodiments described above may be extended to n units atthe first location and n single units. In further embodiments, throughcompositing, more than n single units may be accommodated. Additionally,it may be possible to connect more than one multi-unit location togetheras well as further single unit locations, as desired.

Embodiments of a subset or all (and portions or all) of the above may beimplemented by program instructions stored in a memory medium or carriermedium and executed by a processor. A memory medium may include any ofvarious types of memory devices or storage devices. The term “memorymedium” is intended to include an installation medium, e.g., a CompactDisc Read Only Memory (CD-ROM), floppy disks, or tape device; a computersystem memory or random access memory such as Dynamic Random AccessMemory (DRAM), Double Data Rate Random Access Memory (DDR RAM), StaticRandom Access Memory (SRAM), Extended Data Out Random Access Memory (EDORAM), Rambus Random Access Memory (RAM), etc.; or a non-volatile memorysuch as a magnetic media, e.g., a hard drive, or optical storage. Thememory medium may comprise other types of memory as well, orcombinations thereof. In addition, the memory medium may be located in afirst computer in which the programs are executed, or may be located ina second different computer that connects to the first computer over anetwork, such as the Internet. In the latter instance, the secondcomputer may provide program instructions to the first computer forexecution. The term “memory medium” may include two or more memorymediums that may reside in different locations, e.g., in differentcomputers that are connected over a network.

In some embodiments, a computer system at a respective participantlocation may include a memory medium(s) on which one or more computerprograms or software components according to one embodiment of thepresent invention may be stored. For example, the memory medium maystore one or more programs that are executable to perform the methodsdescribed herein. The memory medium may also store operating systemsoftware, as well as other software for operation of the computersystem.

Further modifications and alternative embodiments of various aspects ofthe invention may be apparent to those skilled in the art in view ofthis description. Accordingly, this description is to be construed asillustrative only and is for the purpose of teaching those skilled inthe art the general manner of carrying out the invention. It is to beunderstood that the forms of the invention shown and described hereinare to be taken as embodiments. Elements and materials may besubstituted for those illustrated and described herein, parts andprocesses may be reversed, and certain features of the invention may beutilized independently, all as would be apparent to one skilled in theart after having the benefit of this description of the invention.Changes may be made in the elements described herein without departingfrom the spirit and scope of the invention as described in the followingclaims.

1. A method for performing a videoconference, the method comprising:establishing, at a first videoconferencing location, a videoconferencebetween at least three videoconferencing locations, wherein the at leastthree videoconferencing locations comprise the first videoconferencinglocation, a second videoconferencing location, and a thirdvideoconferencing location, wherein the first videoconferencing locationmaintains a first plurality of videoconferencing units, wherein thesecond and third videoconferencing locations each maintain a singlevideoconferencing unit, wherein each videoconferencing unit has acorresponding at least one display and at least one video input, whereina first videoconferencing unit of the first videoconferencing locationacts as a multipoint control unit (MCU) of the videoconference; thefirst videoconferencing unit receiving respective videoconferencinginformation from each videoconferencing unit of the videoconference; thefirst videoconferencing unit providing active videoconferencinginformation of an active participant to ones of the videoconferencingunits at the second and third videoconferencing locations correspondingto non-active participants; the first videoconferencing unit providingsecond and third videoconference information from the videoconferencingunits of the second and third videoconferencing locations forpresentation at the first videoconferencing location, wherein saidproviding the second and third videoconference information is performedindependently of the active participant.
 2. The method of claim 1,wherein the active videoconferencing information corresponds to avideoconferencing unit of the first videoconferencing location, whereinsaid providing active videoconferencing information is performed to bothof the videoconferencing units of the second and third videoconferencinglocations.
 3. The method of claim 2, wherein none of thevideoconferencing units of the first videoconferencing location presentthe active videoconferencing information of the videoconferencing unitof the first videoconferencing location.
 4. The method of claim 1,wherein the active videoconferencing information corresponds to thevideoconferencing unit of the second videoconferencing location, whereinthe active participant corresponds to the videoconferencing unit of thesecond videoconferencing location, wherein said providing activevideoconferencing information is not performed to the videoconferencingunit of the second videoconferencing location, and wherein saidproviding active videoconferencing information is performed to thevideoconferencing unit of the third videoconferencing location.
 5. Themethod of claim 1, wherein the first videoconferencing unit provides thesecond videoconference information for presentation by the firstvideoconferencing unit, and wherein the first videoconferencing unitprovides the third videoconferencing information for presentation by asecond videoconferencing unit of the first videoconferencing location.6. The method of claim 1, further comprising: determining an activeparticipant of the videoconference; wherein said providing the activevideoconferencing information is performed based on said determining. 7.The method of claim 1, further comprising initiating thevideoconference, wherein said initiating comprises: the firstvideoconferencing unit receiving information from the videoconferencingunit of the second videoconferencing location indicating that the secondvideoconferencing location only includes a single videoconferencingunit; the first videoconferencing unit receiving information from thevideoconferencing unit of the third videoconferencing locationindicating that the third videoconferencing location only includes asingle videoconferencing unit.
 8. The method of claim 1, wherein thefirst videoconferencing location further comprises a thirdvideoconferencing unit, wherein the videoconference includes a fourthvideoconferencing location which includes a single videoconference unitwith a corresponding at least one display and video input, and whereinthe method further comprises: the first videoconferencing unit providingactive videoconferencing information to the videoconferencing unit ofthe fourth videoconferencing location when the active videoconferencinginformation does not correspond to the fourth videoconferencinglocation; the first videoconferencing unit providing fourthvideoconference information from the videoconferencing unit of thefourth videoconferencing location for presentation at the firstvideoconferencing location.
 9. The method of claim 1, furthercomprising: the first videoconferencing unit providing a composite videoto the videoconferencing unit of the second videoconferencing location,wherein the composite video comprises video from a plurality of: thefirst videoconferencing unit of the first videoconferencing location, asecond videoconferencing unit at the first videoconferencing location,and the videoconferencing unit at the third videoconferencing location.10. A computer accessible memory medium storing program instructions forperforming a videoconference, wherein the program instructions areexecutable to: establish, at a first videoconferencing location, avideoconference between at least three videoconferencing locations,wherein the at least three videoconferencing locations comprise thefirst videoconferencing location, a second videoconferencing location,and a third videoconferencing location, wherein the firstvideoconferencing location maintains a first plurality ofvideoconferencing units, wherein the second and third videoconferencinglocations each maintain a single videoconferencing unit, wherein eachvideoconferencing unit has a corresponding at least one display and atleast one video input; receive respective videoconferencing informationfrom each videoconferencing unit of the videoconference; provide activevideoconferencing information of an active participant to ones of thevideoconferencing units at the second and third videoconferencinglocations corresponding to non-active participants; provide second andthird videoconference information from the videoconferencing units ofthe second and third videoconferencing locations for presentation at thefirst videoconferencing location, wherein said providing the second andthird videoconference information is performed independently of theactive participant.
 11. The memory medium of claim 10, wherein theactive videoconferencing information corresponds to a videoconferencingunit of the first videoconferencing location, wherein said providingactive videoconferencing information is performed to both of thevideoconferencing units of the second and third videoconferencinglocations.
 12. The memory medium of claim 11, wherein none of thevideoconferencing units of the first videoconferencing location presentthe active videoconferencing information of the videoconferencing unitof the first videoconferencing location.
 13. The memory medium of claim10, wherein the active videoconferencing information corresponds to thevideoconferencing unit of the second videoconferencing location, whereinthe active participant corresponds to the videoconferencing unit of thesecond videoconferencing location, wherein said providing activevideoconferencing information is not performed to the videoconferencingunit of the second videoconferencing location, and wherein saidproviding active videoconferencing information is performed to thevideoconferencing unit of the third videoconferencing location.
 14. Thememory medium of claim 10, wherein the second videoconferenceinformation is provided for presentation at a first videoconferencingunit of the first videoconferencing location, and wherein the thirdvideoconferencing information is provided for presentation by a secondvideoconferencing unit of the first videoconferencing location.
 15. Thememory medium of claim 10, wherein the program instructions are furtherexecutable to: determine an active participant of the videoconference;wherein said providing the active videoconferencing information isperformed based on said determining.
 16. The memory medium of claim 10,wherein the program instructions are further executable to initiate thevideoconference, wherein said initiating comprises: receivinginformation from the videoconferencing unit of the secondvideoconferencing location indicating that the second videoconferencinglocation only includes a single videoconferencing unit; receivinginformation from the videoconferencing unit of the thirdvideoconferencing location indicating that the third videoconferencinglocation only includes a single videoconferencing unit.
 17. The memorymedium of claim 10, wherein the first videoconferencing locationcomprises a first, second, and third videoconferencing unit, wherein thevideoconference includes a fourth videoconferencing location whichincludes a single videoconference unit with a corresponding at least onedisplay and video input, and wherein the program instructions arefurther executable to: provide active videoconferencing information tothe videoconferencing unit of the fourth videoconferencing location whenthe active videoconferencing information does not correspond to thefourth videoconferencing location; provide fourth videoconferenceinformation from the videoconferencing unit of the fourthvideoconferencing location for presentation at the firstvideoconferencing location.
 18. The memory medium of claim 10, whereinthe program instructions are further executable to: provide a compositevideo to the videoconferencing unit of the second videoconferencinglocation, wherein the composite video comprises video from a pluralityof: a first videoconferencing unit at the first videoconferencinglocation, a second videoconferencing unit at the first videoconferencinglocation, and the videoconferencing unit at the third videoconferencinglocation.
 19. A videoconferencing system for use at a firstvideoconferencing location, the videoconferencing system comprising: avideoconferencing unit, configured to operate as a multipoint controlunit (MCU) for a videoconference; at least one display coupled to thevideoconferencing unit; at least one video input coupled to thevideoconferencing unit; wherein the videoconferencing unit is configuredto: establish a videoconference between at least a secondvideoconferencing unit at the first videoconferencing location, avideoconferencing unit at a second videoconferencing location, and avideoconferencing unit at a third videoconferencing location, whereinthe second and third videoconferencing locations each maintain a singlevideoconferencing unit, wherein each videoconferencing unit has acorresponding at least one display and at least one video input; receivevideo input from a first participant via the at least one video input;generate videoconferencing information from the audio and video; receiverespective videoconferencing information from each othervideoconferencing unit of the videoconference; provide activevideoconferencing information of an active participant to ones of thevideoconferencing units at the second and third videoconferencinglocations corresponding to non-active participants; provide secondvideoconferencing information from the videoconferencing unit of thesecond videoconferencing location for presentation on the at least onedisplay; provide third videoconferencing information to the secondvideoconferencing unit of the first videoconferencing location forpresentation; wherein said providing the second and thirdvideoconference information is performed independently of the activeparticipant.
 20. The videoconferencing system of claim 19, wherein theactive videoconferencing information corresponds to a videoconferencingunit of the first videoconferencing location, wherein said providingactive videoconferencing information is performed to both of thevideoconferencing units of the second and third videoconferencinglocations, wherein none of the videoconferencing units of the firstvideoconferencing location present the active videoconferencinginformation of the videoconferencing unit of the first videoconferencinglocation.
 21. The videoconferencing system of claim 19, wherein theactive videoconferencing information corresponds to thevideoconferencing unit of the second videoconferencing location, whereinthe active participant corresponds to the videoconferencing unit of thesecond videoconferencing location, wherein said providing activevideoconferencing information is not performed to the videoconferencingunit of the second videoconferencing location, and wherein saidproviding active videoconferencing information is performed to thevideoconferencing unit of the third videoconferencing location.